Method of welding



March 14, 1933. G CLAWSON 1,901,176

METHOD OF WELDING Filed Jan. '7, 1932 2 Sheets-Sheet l /gr f @Lax/95012 G, c. LAWSON 1,901,176

METHOD OF WELDI NG March 14, 1933.

Filed Jan. '7, 1952 2 Sheets-Sheet 2 glnvcnloz j Patented Mar. 14, 19,33

UNITED STATES .PATENT OFFICE GOTTFRID C. LAWSON, Or CANTON, OHIO, AssIeNOR To THE UNITED METAL PRODUCTS COMPANY, or CANTON, OHIO,'A CORPORATION OF OHIO l METHOD 0F WELDING l The invention relates to the manufacture of sheet metal doors and the llke, and more Vespecially to an improved method of welding flush panel doors and similar structures in which two spaced Hat sheets are connected to the edge portions of intervening metal the strips between opposite lugs thereon, fusing the lugs and welding them to the adjacent portions of the sheets.

It hasl been found that by this method of welding the strips to the outer sheets, depressions are formed in the sheets at the points where they are welded to the strip. These depressions considerably mar the appearance of the door and in Order to compensate for the same it is necessary to fill them with the putty composition ordinarily used for covering the surfaces of metal doors and the like.

Even with this putty filling it is not possible to produce a flat surface upon the Outside of thenished door.

rlhe object of the present improvement is to provide a method of welding such structures together so that no depressions are formedin thetsheets, the outer sides of which will present uniform flat surfaces when iinishe It is believed that the depressions produced in the sheets by present practice of welding are'due to the heating ofA the central or inner portion of the strip between lugs causing a shrinkage in the width of the strip as the same contracts upon cooling.

The Objects' of the present improvement may be attained by forming apertures or openings in the edge portions of the strip adjacent to the lugs so .as to prevent the central or inner portion of the strip from becoming highly heated by the welding Operation, thus preventing transverse shrinkage of the strip and producing a finished article in which the outer surfaces of the sheets are flat and uniform throughout.

An embodiment of the invention is illustrated in the accompanying drawings, in which Figure l is a transverse sectional View through a portion of a flush panel doory or the like in position for welding under the present practice;

Fig. 2, a similar View showing the same after welding;

Fig. 3, a `view similar to Fig. l, showing one method of carrying out the present invention;

Fig. 4, a similar' view showing the parts after welding;

Fig. 5, a view similar to Fig. 3, showing a slightly modified form of the invention;

Fig. 6, a similar view showing the parts after welding;

F ig. 7 a view similar to Fig. 3, showing another modification `of the invention;

Fig. 8, a similar view showing the parts after welding;

Fig. v9, a fragmentary perspective View of a portion of one of the strips shown in Figs. 7 and 8;

Fig. 10, an enlarged transverse sectional View `through the strip shown in 3; and

Fig. 11, a similar view showing a slightly modified form of strip.

Similar numerals refer to similar parts throughout the drawings.

In Figs. 1 and 2 is illustrated the usual method of constructing flush panel doors and the like in which the door-consists of two metallic sheets or plates 10 between which are arranged a plurality of flat sheet metal strips 1l located in planes transverse to the planes of the surface sheets 10 and provided at a plurality of separated points along their edges with lugs or projections 12.

The projections along one edge of cach strip ll are directly oposite those on the opposite edge, so that when joining the parts together the welding current may be passed through one sheet 10 to a lug 12 on the underlying strip 11 and then through the lug 12 on the opposite edge of the strip and through the opposite sheet 10, thus effecting two welds at one operation. v l

In Fig. 2 isillustrated the structure shown in Fig. l after the welding operations have been completed, welds 12 being formed between the strip 1l and surface sheets 10 at each point where the lugs 12 were originally located upon the strip. 0.

By formingthese two welds in a `slngle operation, not only the lugs and4 adjacentV 'portions of the surface sheets are heated to a `high temperature, but' by conductivity the provide uniform flat surfaces upon both ofv ythe surface sheets, the p resent inventlon concentral or inner portion of the strip is heated to such an extent. that upon cooling the stripcontracts at the points adjacent to thewelds, pulling the surface sheets in-ward and forming depressions 13 whichare very unsightly in the finished door.

In order toovercome this difficulty and to manner and provided-at spaced intervals on i "opposite edges with lugs or projections 12a,

openings or apertures 14being provided in the edge portions ofthe strip adjacent to and transversely, alined withk said lugs'.

The lugs. may be formed by punching or slitting the stripvnear its edge, punching'the lug outward forming a substantially half-v round aperture as shown at 14. These aper- 5." sure are applied to the surface sheets-10 aty tures may be straight through the strip as at 14 in Fig. l0 or may be tapered as shown fat 14 in Fig. 11, beingl formed by a bevel ledgedI tool or the like.

' With the parts placed Iin the position 'l lshown in Fig. 3, electric current and pres.

points adjacent to the lugs 12a, heating the lugs' to Welding temperature and pressing them inward, -forming' welds between the upon the sheets 10, as'shown in Vsaid figure.

surface sheets and the. strip as indicated at 13a, the apertures v14 beingl substantially:

closed bythe Figa 4.

Since the apertures 14 prevent the heat of the portions being welded from being conwelding operation, as shown in ducted toward the center of the strip, there is no contracting or transverse shrinking of the strlp,xprovidi ng flat uniform surfaces The width of the'lug 12a as well as the length thereof should/ vary in accordance` with the thickness of the strip 11a.- The length ofthe lug should be between two and three times its width to obtain the best re-` sults and the width of the lug should decrease as the thickness of the strip is increased in :order that the proper volume of metal be maintained in the lug to produce the best results in welding.

The invention may be carried out by foi-n1- ing the lugs 12b`upon -the strip 1lb in the manner shown .in Fig. 5 and providing sub-- stantially circular apertures 14!) in the edge ortions of the strip adjacent to and preferaly transversely alined with said -lngs for the purpose of preventing heating of the central portionof the strip by conductivity from the heat of the weld.

The surface sheets 10 are placed against f the .lugs as shown in Fig. 5 and the welding is accomplished in usual manner, melting down .the lugs and forming welds as atlB),

between the stripand the surface sheets, and distorting the apertures 1425 to elliptical shape as shown in Fig. 6. Y

If desired, the ystrips may be of channel formy as shown at 110 in Figs. 7, 8 and 9, being provided at theiredge portions with'the angular flanges 15. v

Each flange is slit at intervals at points spaced from the outer edge thereof as shown at 16 and the metal between said slit and the outer edge of the flange is pressed outward,

formin a projection or lug 12e against which.

the sur ace sheets 10 are adapted to be placed. When the 'parts are welded as in usual practice, they assume the'position shown in ig. 8, the surfacesheets 10 being welded to the anges 15-of the strip 11e as at 130,.I the outer surface of the lsheets 10 being flat and uniform throughout. j

Itv will thus be seen that under theinvention above described in detail vflush panel doors and the like may be .formed so that there are no depressions in the surface sheets l at the points where the welds are Aformed this being made possible by the formation of apertures or openings in the' edge portions of the transverseI strips adjacent tol theprojections or lugs thereon so as to prevent heating of the central, or inner portion'of the'strip, thus obviatingthe contraction or shrinking of the strip in width atpoints adjacent to the welds.

The improved method of welding disclosed hereiny produces a more resilient or elastic weld than is possible by the old way ofwelding the surface sheets direct to the strip. This resilience or elasticit is especially desirable in structures such asA cors andthe like which are subjected to considerable vibration .in

use.

It has been found by ex rience that the imtwenty per cent less electric ower to weld the parts together than is required by the ,old

proved method of wel ingv requires about i 65 pointsspace method, thus not only producing a better structure physically as well as in appearance but'lessening the cost over the old method.

I claim:

1. The method of welding a sheet metalldoor and the like, consisting forming pro-l jections upon opposite edges of a metal strip and `forming openings inthe edge portions of the strip .adjacent to and transversely alined with said projections, placing the strip between two parallel sheetl metal plates with the strip disposed in a plane transverse to the planes of said plates, and then welding the'plates to' said strip through said'pro- '15 jections.

2. The method of welding a sheet metal door and the like, consisting in forming projections upon opposite edges of a metal strip and forming substantially half-round openv ings in the edge portions of the strip adjacent the edge portions ofthe strip adjacent -to and p l ltransversely alined with said projections,

placing the strip between two arallel sheet `metal plates with the strip' isposed in a plane transverse to the planes of said plates, andthen weldin the plates to'said strip through said projections.

4. The,meth.od .of Welding'a sheet metal door and the-like, consisting in forming sulsite edoes of a metal .strip and forming'substantially half-round (penings inthe edge portions of the strip a jacent to and transversely alined with said projections, placing the strip between two' arallel sheet metal plates with the strip isposed in a plane transverse to the planes of said lates, and

then welding the plates to said strip through said projections. l

' 5. The^ method' of welding a sheet metal door and the like, consisting in forming projections upon opposite edges of a metal strip by punching openings in the edge portions of the strip and punching the edges of the strip l outward adjacent to said openings, placin I the strip between two parallel s eet met plates with the strip disposed. inl a plane transverse to the planes o said plates, and

x then welding theplates to said strip'through e0 I said projections. 6. The method of welding a sheet metal door and the like, consisting in forming anl gular flanges at -op ositeedges of a metal stantially half-round projections'upon oppoing the edge portions of the 'flanges outward v forming projections adjacent to said slits, placing the stri between two parallel sheet metal plates wit the strip disposedin a plane transverse to the planes of said plates, and then welding the plates to thestrip through said rojeetions.

7 e method of welding a sheet metal door 'and the like, consisting in forming angula-r'langes at opposite edges of a metal strip, cuttm slits in said anges, punching portions of t e ianges outward forming projections adjacent to said slits, placing the strip between two parallel sheet metal plates with the strip dis osed in a plane transverse to the planes of said plates, and then welding the plates to the strip through said projections. s

In testimony that I claim the above, 1

have hereuntofsubscribed my name.

GOTTFRID C. LAWSON.

'loo strip, cuttm 'space slits in said an l at A.

from the edges thereof, punclh- 

